Fuel issues

[LT67]

Thanks for your reply. Based on my looking around there does not appear to have been any mechanical parts replaced.

Thanks,
Ned

If you have to replace it, make sure you get Delphi #CHFP906. That is the correct pump. Delphi #MF0030 will not work even thought the parts houses have it listed as the correct pump.

 

[nedbread]

I ordered a pump

If you have to replace it, make sure you get Delphi #CHFP906. That is the correct pump. Delphi #MF0030 will not work even thought the parts houses have it listed as the correct pump.

Thanks,
I have not tried the diagnosis of the lift pump yet. However every time I prime the system (crank with the pink cable disconnected from the IP, the cap off the tank, and the vent plug on the fuel filter mount loosened) I get fuel squirting out of the 'vent plug port' right away. So I figure the lift pump is working at least enough to get the fuel up there.

 

[LT67]

I ordered a pump


Thanks,
I have not tried the diagnosis of the lift pump yet. However every time I prime the system (crank with the pink cable disconnected from the IP, the cap off the tank, and the vent plug on the fuel filter mount loosened) I get fuel squirting out of the 'vent plug port' right away. So I figure the lift pump is working at least enough to get the fuel up there.

The lift pump on my 86 m1008 recently had to be replaced and the parts store sent MF0030 to the shop. Lol, it barely ran. Yesterday the correct pump CHFP906 was installed. It runs again lol

 

[Barrman]

There are two kinds of white smoke:

Fluffy white that has an antifreeze smell. Normally this means head gasket issues.

Dirty white with a diesel tint to it. This means not enough heat. If you are getting a continuous cloud, not just a puff at start up. Then once it is running, you are not getting fuel to all your cylinders or very little to all of them. Which you already know.

There is a hose on the top of the injection pump pointed toward the radiator. it is held on with a red squeeze clamp. Pull the hose and use a 9/16 socket to pull the fitting off the pump. Then, look inside the fitting. There should be a glass ball check valve in there with a spring. If you see nothing in there. Then someone removed the guts because the IP was coming apart internally. If you see the glass ball and a bunch of black bits. Then your IP is coming apart internally and needs to be rebuilt.

However, your trouble filling the fuel tank sounds like a possibly related issue or maybe a complete separate issue that still needs to be fixed. Have you tried running the truck with the fuel cap off?

 

[Mad Texan]

By the way, I am also interested in taking the tank off anyway. There are 4 bolts to take off the support brackets. One of these bolts is obscured, and it seems like the only way to get it off is to remove a bit of plate held onto the frame by two big 3/4 inch bolts with nuts. Is that familiar?

Here is a little sketch of 4 bolts holding on the rear support bracket.

Yes you have to remove a little of the plate to get a socket on that bolt. If you have a die grinder with a whiz wheel it can be done quickly. I believe it is unique to the M1010 only. I had to do it on both sides as I replaced the original tank and added one on the passenger side.

 

[nedbread]

Yes you have to remove a little of the plate to get a socket on that bolt. If you have a die grinder with a whiz wheel it can be done quickly. I believe it is unique to the M1010 only. I had to do it on both sides as I replaced the original tank and added one on the passenger side.

Thank you that is what I figured...

 

[nedbread]

There are two kinds of white smoke:

Fluffy white that has an antifreeze smell. Normally this means head gasket issues.

Dirty white with a diesel tint to it. This means not enough heat. If you are getting a continuous cloud, not just a puff at start up. Then once it is running, you are not getting fuel to all your cylinders or very little to all of them. Which you already know.

There is a hose on the top of the injection pump pointed toward the radiator. it is held on with a red squeeze clamp. Pull the hose and use a 9/16 socket to pull the fitting off the pump. Then, look inside the fitting. There should be a glass ball check valve in there with a spring. If you see nothing in there. Then someone removed the guts because the IP was coming apart internally. If you see the glass ball and a bunch of black bits. Then your IP is coming apart internally and needs to be rebuilt.

However, your trouble filling the fuel tank sounds like a possibly related issue or maybe a complete separate issue that still needs to be fixed. Have you tried running the truck with the fuel cap off?

I will look at the check valve tomorrow. Is the IP replacement in any of the TM's?

The filling up issue is a clogged vent tube. I am removing the tank and will confirm.

(If the fuel system is primed the engine would run normally even with both fill and vent tube stopped up)

 

[Barrman]

Yes, the -34 manual covers removal as does the HMMWV -34 manual. To me the hardest part is the one arm push ups required to do the job. Some kind of powered socket driver makes this a lot better.

Pull the intake manifold.

Pull the fuel injector metal lines. An 11/16” crow foot wrench is really needed for this. I forget the proper metric one. With a 3/4” open end to hold the injector still. I haven’t done this in a few months so it could be a 7/8”.

You need a socket and breaker bar to turn the crank shaft. Pull the oil fill tube off the engine. Turn the crank until one of the 3 bolts holding the gear to the IP shaft is centered in the hole. A trick I use is put a cardboard toilet paper roll tube in there to catch the bolt once a 13mm socket gets it off. Repeat for the other 2 bolts After turning the crank. The gear stays in there and makes it so you can’t be out of time since the IP shaft has a pin that only fits in the gear one way.

Unplug the 2 green wires and the pink wire. I like to use a 15 mm u-joint or swivel socket to get the lower IP mount bolts and a combination wrench for the top one.

Pull the 1/4” fuel line and remove the IP. Replace all the flexible fuel hoses with new biodiesel safe ones while you have access and will have to bleed the system anyway. Now would also be a good time to put on a spin on fuel filter if you were thinking about it.

Assembly is the reverse of disassembly. The metal fuel lines only go on one way and only fit one cylinder. If you are having to bend them, you have the wrong one in hand. Make sure each end of each line is clean. A single spec of dirt will cause a leak or crack the line end. There is a torque spec for the lines. However start just a tad tight than hand tight and leave them alone if they don’t leak. The injector ends will need to be loosen for bleeding, so no point in doing more than that until you get fuel flowing.

 

[Keith_J]

How many miles on the odometer? Any chain slap noise from the timing chain cover? This is noticeable at idle speed when the timing chain set is worn. This will delay injection timing, causing the white smoke and other symptoms. Timing is advanced when cold, when the engine warms, the timing reverts to normal which could cause issues with a worn chain. Try jumping 12 volts to the cold idle solenoid and timing advance to see if both work. If this solves the engine dying when warm symptom, this is the issue. This is the green wires to the injection pump. You should see the throttle advance with 12 volts, it may not be enough to move the throttle so blip the throttle open to set high idle.

I have done this repair. 70 k unknown miles, 1986 M1009. Probably spent too much time idling in its prior life. Slack was well over the limit of 1\2 inch and slapping the case. You remove all belts, alternators, water pump, harmonic damper and disconnect the injection pump from the sprocket. So if there are any injection pump issues like throttle shaft leak, replace the injection pump with the timing set.

The only special tool is the puller for the harmonic damper.

 

[Barrman]

I forgot about even asking about the timing. Good call Keith. What is the timing mark at?

 

[nedbread]

How many miles on the odometer? Any chain slap noise from the timing chain cover? This is noticeable at idle speed when the timing chain set is worn. This will delay injection timing, causing the white smoke and other symptoms. Timing is advanced when cold, when the engine warms, the timing reverts to normal which could cause issues with a worn chain. Try jumping 12 volts to the cold idle solenoid and timing advance to see if both work. If this solves the engine dying when warm symptom, this is the issue. This is the green wires to the injection pump. You should see the throttle advance with 12 volts, it may not be enough to move the throttle so blip the throttle open to set high idle.

I have done this repair. 70 k unknown miles, 1986 M1009. Probably spent too much time idling in its prior life. Slack was well over the limit of 1\2 inch and slapping the case. You remove all belts, alternators, water pump, harmonic damper and disconnect the injection pump from the sprocket. So if there are any injection pump issues like throttle shaft leak, replace the injection pump with the timing set.

The only special tool is the puller for the harmonic damper.

Hi Keith,

This truck has 31,000 miles. I don't hear any metal on metal though the belts do fly around like mad and the engine shakes something terrible. Not noticeable in terms of driving performance just loud.

I think you are advising another diagnostic that should be done before the IP swap. Something about the timing chain being too lose. I can check this tomorrow. Thanks!

 

[nedbread]

I forgot about even asking about the timing. Good call Keith. What is the timing mark at?

I will check the timing mark how do I identify it and where on the engine is it?

Thanks,
Ned

 

[Keith_J]

I forgot about even asking about the timing. Good call Keith. What is the timing mark at?

Driver side engine by the harmonic damper. But unless you have a diesel pickup timing light..
The noise will get bad before the timing is impacted..indirect injection has a wide window.
Guess I will look for an old school diesel timing light.

 

[Sharecropper]

Driver side engine by the harmonic damper. But unless you have a diesel pickup timing light..
The noise will get bad before the timing is impacted..indirect injection has a wide window.
Guess I will look for an old school diesel timing light.

Yeah I’m looking for one of those timing lights too. Surely some company is offering them. Snap-On maybe?

 

[Keith_J]

Yeah I’m looking for one of those timing lights too. Surely some company is offering them. Snap-On maybe?

Sealey TL95. 168 doll hairs plus change from the usual scumbags. That is a UK brand. And this is an E-dapter kit which makes a gasamoline timing light chooch on a die easel. So you might needs to run down to Hazard Fraught and plop twenty clams on one of them. Sure beets a Fap Off over priced piece a garbage.
83% five stars on Dr Evil's website. 7% 4 stars and 10% 3 stars. Do the math, looks good enough for the women I go out with.

 

[Sharecropper]

Sealey TL95. 168 doll hairs plus change from the usual scumbags. That is a UK brand.

Thanks. Just bought thu sucka.

 

[Keith_J]

Thanks. Just bought thu sucka.

Noticed that. Inventory dropped by 1. Realize it is shipped by the vendor, that being whybee adventure. Good ratings. But the trip over the pond is 11 dollars. Won't get the VAT hit and no tarrriff on automotive tools so if you can wait, should be kosher.

 

[Mad Texan]

I was interested in using the auxiliary fuel pickup, and because you said a metal pipe with a rubber cap I was pretty sure I knew what you were talking about. However, the line that I was thinking of, which comes right from the top middle of the tank, along with the other two lines, is called in the TM a "drain pipe." When I originally connected a hose to this and put the other end of the hose in a gas can, basically nothing happened. The truck turned over and would not start. Today I bled the air, or primed, and got it 'running' (sort of) again. When I uncapped this drain pipe fuel ran out and I had to bleed the air again. Is that normal? Should I try priming with the end of a hose from this drain pipe in a gas can? Is this the line you're talking about?

Some thoughts.... It doesn't sound like you hooked up the drain line properly to feed the fuel system. You would need to run a hose from the drain line on the drivers side to metal line on the passenger side (bottom metal line on the left in second pic) which is under a cover and then bleed the system. This would tell you is the sock is clogged.

Secondly... If dropping a tank may I recommend picking up hydraulic lift cart. Because even when you think the tanks empty, it's not. And when fuel sloshes without any baffles weight shifts fast. When I pulled this tank by myself to plumb for my heater recently, it was about half full. It made it rather easy.

Third... rubber lines. Replace them, especially between the tank and the lift pump. The feed lines are all under vacuum while the engine is running so a small pin hole may let air in but not show a leak. When you bleed the system, you fill the fuel filter and give the injection pump a fuel source until air starts bleeding in again. They are 30+ years old. As well @cucvrus has said the same for the metal line from the tank to the passenger side getting corroded and letting air in. Check it well.

For the lift pump on the M1010, pull the alternators to gain more access to it. Replace the rubber hoses at it as well. @antennaclimber found the formed curved S hose from a corvette is similar to ours which is discontinued. Use grease to hold the pump push rod in place when reassembling.

Injection pump, isn't terrible to do. More than four hours on the M1010 with the alternators and the AC to deal with. And it gives you some time to clean things up.

 

[nedbread]

Some thoughts.... It doesn't sound like you hooked up the drain line properly to feed the fuel system. You would need to run a hose from the drain line on the drivers side to metal line on the passenger side (bottom metal line on the left in second pic) which is under a cover and then bleed the system. This would tell you is the sock is clogged.

Secondly... If dropping a tank may I recommend picking up hydraulic lift cart. Because even when you think the tanks empty, it's not. And when fuel sloshes without any baffles weight shifts fast. When I pulled this tank by myself to plumb for my heater recently, it was about half full. It made it rather easy.

Third... rubber lines. Replace them, especially between the tank and the lift pump. The feed lines are all under vacuum while the engine is running so a small pin hole may let air in but not show a leak. When you bleed the system, you fill the fuel filter and give the injection pump a fuel source until air starts bleeding in again. They are 30+ years old. As well @cucvrus has said the same for the metal line from the tank to the passenger side getting corroded and letting air in. Check it well.

For the lift pump on the M1010, pull the alternators to gain more access to it. Replace the rubber hoses at it as well. Someone found the formed curved S hose from a corvette is similar to ours which is discontinued. Use grease to hold the pump push rod in place when reassembling.

Injection pump, isn't terrible to do. More than four hours on the M1010 with the alternators and the AC to deal with. And it gives you some time to clean things up.

Thanks, are all these fuel lines 5/16"? Secure with a tiny hose clamp? Looks like you got the box off. Did you do that for the tank job? By the way-- took a look at the gram, hoping to get mine looking and functioning something like that someday!

 

[Mad Texan]

Thanks, are all these fuel lines 5/16"? Secure with a tiny hose clamp? Looks like you got the box off. Did you do that for the tank job? By the way-- took a look at the gram, hoping to get mine looking and functioning something like that someday!

No, they are 3/8, 5/16, and 1/4'. Somewhere there is a thread with approximate lengths but I can't find it. If you bought 3' of each you should have extra for spares if I remember correctly, so not a big expense. I found this finally: Fuel Lines

If you're replacing rubber lines, don't forget the vacuum lines as well...

I haven't had the ambulance box off, I found that pic here on the site and pirated it without giving credit as an example. There is a picture of the bolt you couldn't get to somewhere around here as well...

Thanks for the compliments! Been a work in progress!